122 University of California Puhlications in Botany [Vol. 5 



plant drawn one-half natural size. Its cauline leaves corres- 

 pond fairly exactly to those in figure 1 of plate 29, except that 

 the waviness along the leaf margins of the leaves of variety II 

 is not so strongly marked in the leaves of the wild variety. The 

 third leaf from the base of the stem in figure 1 of plate 30 re- 

 sembles figure 6 of plate 29, while figure 7 of plate 30 approxi- 

 mates the appearance of the leaf shown in figure 7 of plate 29, 

 though in this last case, and as is very evident, the narrow 

 leaf -tip of the wild variety does not arise so sharply from the 

 broad cordate leaf-base as in the leaf of variety II. The corolla 

 tubes of the flowers shown in plate 30 are both longer in pro- 

 portion to the size of the flower and somewhat more dilated at 

 the top than in the flowers of variety II. The calyx teeth also are 

 longer in the flower and the calyx in the ripening ovary does 

 not so completely envelop the maturing seed capsule as in the 

 cultivated variety. 



Varieties I and II have been grown in a number of Botanical 

 Gardens under such names as Nicotiana vincae/lora,, N. suaveo- 

 lens, as well as N. acuminata. 



In the three varieties of N. acuminata described above we 

 have individuals identical, within the limits of normal individual 

 fluctuation, in almost every respect except the diameter of the 

 flattened salverform corolla. This point of difference is plainly 

 marked and entirely constant. On the first occasion, four years 

 ago, upon which the three were assembled and grown near one 

 another, Professor W. A. Setchell observed the sharp gradation 

 in this character and the absence of other distinguishing and 

 delimiting characteristics. During the past two years, in which 

 this species has been turned over to me, a large number of 

 measurements and careful examination confirm these observa- 

 tions. As has been said, the present paper deals with the general 

 appearance and corolla diameter of the first hybrid generation 

 resulting from crosses between these three varieties of N. acumin- 

 ata. Seed is being gathered at the present time which will make 

 it possible to continue the investigation along the same lines in 

 the Fo and, possibly, the Fg generation. 



